Research in context
Evidence before this study
Individual studies have previously investigated the effect of increasing antibiotic resistance on a reduction in the efficacy of antibiotic prophylaxis, but a global estimate of the effect of declining antibiotic efficacy is unknown. We did two main literature searches: one to identify studies published between January, 1950, and May, 2015, that investigate the efficacy of antibiotic prophylaxis on clinical outcomes of surgical procedures and cancer chemotherapy, and one to review the existing evidence on the effect of antibiotic resistance on clinical outcomes (including infection and mortality rates) for the same procedures (studies published between January, 1990, and May, 2015). No language restrictions were applied. Besides the different meta-analyses and reviews listed for each procedure in appendix pp 11–12, we identified two main reviews that studied the efficacy of antibiotic prophylaxis in preventing infections across different surgical procedures. By contrast, the published literature about the effects of antibiotic resistance on infection rates after various medical procedures was sparse. We were able to identify studies of the effects of changes in prophylactic regimens on infection rates for several procedures.
Added value of this study
To our knowledge, this study provides the first estimates of the potential effect of antibiotic resistance on the efficacy of antibiotic prophylaxis for a range of surgeries and cancer treatments. By using data from the published literature on both the effects of antibiotic prophylaxis on infection rates and on the effects of antibiotic resistance on infections rates for different procedures, we were able to provide estimates of the potential effect of antibiotic resistance on clinical outcomes after major medical procedures.
Implications of all the available evidence
Our study confirms findings that increasing antibiotic resistance potentially threatens the safety and efficacy of surgical procedures and immunosuppressing chemotherapy. These results provide a basis for further studies investigating the effects of antibiotic resistance on infection rates and other clinical outcomes across a wide range of medical procedures.